How can I print all 5 or 6 pages of the thread?
Click
HERE 
I believe this PPRuNe printing glitch has been around for some time.
As a work around, for any other multi-page threads you wish to print, try this:-
Right click on 'print' at the bottom of the page and left click on 'Open in New Window' - then at end of the url add:-
&perpage=1000 and hit Return/Enter.
This will show 1000 posts per page, and enables viewing and printing of all posts and pages in 'printer friendly format'.